Thinning large thighs are a common exercise goal, which can be achieved through a range of resistance exercises and cardio workouts. However, the size of your thighs are determined genetically, which means that while you can tone and shape up thighs with lower body exercises to give them a thinner appearance, there will only be so much you can do. Furthermore, you can’t spot reduce parts of your body — to lose body weight and fat, you need to lose weight and fat overall.

Distance Running

Cardio workouts are the most efficient way of burning calories, helping you lose body weight and fat. According to the American Heart Association, 30 minutes of moderate intensity cardio five days a week is recommended to maintain general fitness levels. To lose bulky thigh muscles, Columbia University suggests distance running, which helps tone legs as well as reducing their size. While you will build leg muscles running, the endurance training required for distance running means you develop leaner muscles. However, if you are not used to running or if you have a history of joint pain or injury, this may not be a good choice for you. Start slowly to get your body used to the new exercise and training regimen and to reduce the risk of injury.

Single-Leg Squat With Towel

This variation on the basic squat works your glutes as well as your quadriceps, building muscle and toning your legs. Standing with your feet hip-width apart, place a towel under your left foot and place your weight on your right leg. Sinking down by bending at your right knee and hip, go into a squat, never letting your knee extend past your toe. Keep your left leg straight and allow it to slide out to the side. Stop when your right thigh is parallel to the floor, and slowly rise back up to starting position, repeating the squat 10 times for three sets and then switch sides.

Leg Curls

Leg curls work your hamstrings as well as calf muscles. Lying with your tummy on the padded bench, place the padded level so that it sits over both legs, near the lower calf and just above the ankle. Raise both legs at the same time, bringing your feet towards your bottom and then slowly lower back to starting position. Repeat the lift 10 times for three sets, increasing the weight as you build leg strength.

Side-Lying Leg Raise

A classic exercise, the side-lying leg raise works your thigh muscles, especially if you use a resistance band or ankle weights to increase resistance. For ankle weights, attach the weight to the ankle of your upper leg. For a resistance band, loop the band around both of your ankles, tying the ends of the band together if you need to. Lying on your right side, with your legs stacked on top of one another, place your right arm below your head for support. Keeping your torso and legs straight, raise your left leg up to 60 degrees, then further to 90 degrees before slowly returning to starting position. Repeat 12 times for three sets and then switch sides.

About the Author

Jessica Lewis has published professionally since 2005 and is a registered dietitian and nutritionist. Her work is regularly found in the "National Post" and "Oxygen Magazine." She holds degrees from the University of Guelph and McMaster University. A marathon runner and yoga enthusiast, she is also interested in alternative medicine.